An In Vitro Model of Bullous Pemphigoid - Complement activation and production of complement-derived chemotactic activity is an important functional property of tissue deposited immune complexes. It has been implicated in the pathogenesis of inflammation in a number of diseases associated with immune complex deposits at the basement membrane zone, but its relative importance in these diseases is not well understood due in part to an inability to quantitate the function and determine its relationship to histologic features of skin lesions. In previous studies of one of the diseases, bullous pemphigoid, methods were developed for measuring this function. In preliminary studies, evidence has been obtained that the ability of immune complexes to express this function varies among diseases and that there is a good correlation between this function and histologic features characteristic of immune complex and complement mediated inflammation. In the present study, we plan to measure this function in a variety of diseases, determine its relationship to histologic features and its relationship to the ability of immune complexes to mediate inflammation in organ culture and experimental animals. Studies on Epidermolysis Bullosa Acquisita Antibodies - Epidermolysis bullosa acquisita (EBA) antibodies are anti-basement membrane zone autoantibodies regarded as specific for the disease, EBA. They can be distinguished from other known anti-basement membrane zone autoantibodies by immunofluorescent and immunoultrastructural criteria and by reactivity with 290 and 145 kd proteins extracted from dermis-lamina densa. We have obtained preliminary evidence that EBA-like antibodies are present in patients with bullous eruption of SLE and nonbullous SLE and in an SLE-like murine model of chronic graft vs. host disease in whom autoantibody production is due to a defined H-2 incompatibility. Our preliminary studies also suggest production of EBA autoantibodies in man is closely linked to a specific class II histocompatibility antigen. In this study, we plan to determine if EBA antibodies are present in the circulation and cutaneous immune deposits in SLE, determine if murine models of SLE are associated with EBA antibodies and characterize the class I and II histocompatibility antigen in patients with EBA antibodies.